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81.
本文报道了多光束共振光压作用下钠原子束偏转的实验研究结果。文中提出了用多光束与原子束相互作用以增大原子束的偏转量,并可大大降低对激光功率的要求。用一台染料激光器照射钠原子束得到1×10-2rad的偏转角,偏转距离约7.2mm,并用激光诱导原子束荧光的方法检测原子束的偏转。 相似文献
82.
The A-type bands, 2ν2 + ν3 and ν1 + ν2 + ν3, with band centers at 3092 and 3638 cm?1, respectively, of 14N16O2 have been measured with resolution of 0.03 cm?1 or better. Spectroscopic constants have been derived for the upper states of both bands. Infrared determined band constants have been combined with laser-excited resonance fluorescence data to obtain a set of vibration and vibration-rotation constants for the ground state of 14N16O2. 相似文献
83.
The ν1 bands of HO35Cl and HO37Cl have been recorded. Both the A- and B-type rotational transitions of these hybrid bands have been completely assigned, and spectroscopic constants have been obtained for both the ground and upper state. The ratio of the electric dipole moment derivatives has been found to be 0.985 ± 0.05 for ν1. 相似文献
84.
The ν1 and 2ν1 bands of OCS have been measured using grating spectrometers and a tunable diode laser spectrometer. Preliminary wavenumbers for OCS absorption lines useful for calibrating tunable laser systems are given for the wavenumber intervals 825 to 885 cm?1 and 1665 to 1737 cm?1. Measurements and an analysis are given for the bands 1000-0000, 1110-0110, 2000-0000, 2110-0110, and 3000-1000 of the 16O12C32S isotopic species and for the 2000-0000 band of the 16O13C32S and 16O12C34S species. Effective band constants are given for these bands. 相似文献
85.
Reaction of iron powder with 1,3,4,7-tetramethylisoindole at 350° affords the square planar complex octamethyl-tetrabenzporphyriniron(II), whose magnetic moment indicates a spin quintet ground state. Mössbauer measurements at 4.2°K in an applied magnetic field of 50 kG show that the electric field gradient at iron is positive and axially symmetric, consistent with a 5B2g ground term. The bistetrahydrofuran adduct is also high spin, whereas the bispyridine adduct is diamagnetic with 1A1g ground state. Comparisons are made with data for the related tetraphenylporphiniron(II) and phthalocyanineiron(II) derivatives. 相似文献
86.
87.
The high-resolution spectrum of H12C14N has been measured near 4870 and 6060 cm−1. The following bands have been identified and analyzed: 0112-0000, 0202-0110, 0222-0110, 0401-0000, 1111-0000, 1201-0110, and 1221-0110. The C---N stretching fundamental (ν3) of H12C15N has also been measured near 2100 cm−1. This fundamental is found to be 3 cm−1 higher than previously reported. Other bands that have been identified in the H12C16N spectrum are 0310-0000, 0400-0110, 0420-0110, and 0111-0110. 相似文献
88.
Blake TA Glendening ED Sams RL Sharpe SW Xantheas SS 《The journal of physical chemistry. A》2007,111(44):11328-11341
We present experimental infrared spectra and theoretical electronic structure results for the geometry, anharmonic vibrational frequencies, and accurate estimates of the magnitude and the origin of the ring-puckering barrier in C4F8. High-resolution (0.0015 cm-1) spectra of the nu12 and nu13 parallel bands of perfluorocyclobutane (c-C4F8) were recorded for the first time by expanding a 10% c-C4F8 in helium mixture in a supersonic jet. Both bands are observed to be rotationally resolved in a jet with a rotational temperature of 15 K. The nu12 mode has b2 symmetry under D2d that correlates to a2u symmetry under D4h and consequently has +/- <-- +/- ring-puckering selection rules. A rigid rotor fit of the nu12 band yields the origin at 1292.56031(2) cm-1 with B' = 0.0354137(3) cm-1 and B' ' = 0.0354363(3) cm-1. The nu13 mode is of b2 symmetry under D2d that correlates to b2g under D4h, and in this case, the ring-puckering selection rules are +/- <-- -/+ . Rotational transitions from the ground and first excited torsional states will be separated by the torsional splitting in the ground and excited vibrational states, and indeed, we observe a splitting of each transition into strong and weak intensity components with a separation of approximately 0.0018 cm-1. The strong and weak sets of transitions were fit separately again using a rigid rotor model to give nu13(strong) = 1240.34858(4) cm-1, B' = 0.0354192(7) cm-1, and B' ' = 0.0354355(7) cm-1 and nu13(weak) = 1240.34674(5) cm-1, B' = 0.0354188(9) cm-1, and B' ' = 0.0354360(7) cm-1. High-level electronic structure calculations at the MP2 and CCSD(T) levels of theory with the family of correlation consistent basis sets of quadruple-zeta quality, developed by Dunning and co-workers, yield best estimates for the vibrationally averaged structural parameters r(C-C) = 1.568 A, r(C-F)alpha = 1.340 A, r(C-F)beta = 1.329 A, alpha(F-C-F) = 110.3 degrees , thetaz(C-C-C) = 89.1 degrees , and delta(C-C-C-C) = 14.6 degrees and rotational constants of A = B = 0.03543 cm-1 and C = 0.02898 cm-1, the latter within 0.00002 cm-1 from the experimentally determined values. Anharmonic vibrational frequencies computed using higher energy derivatives at the MP2 level of theory are all within <27 cm-1 (in most cases <5 cm-1) from the experimentally measured fundamentals. Our best estimate for the ring-puckering barrier at the CCSD(T)/CBS (complete basis set) limit is 132 cm-1. Analysis of the C4F8 electron density suggests that the puckering barrier arises principally from the sigmaCC-->sigmaCF hyperconjugative interactions that are more strongly stabilizing in the puckered than in the planar form. These interactions are, however, somewhat weaker in C4F8 than in C4H8, a fact that is consistent with the smaller barrier in the former (132 cm-1) with respect to the latter (498 cm-1). 相似文献
89.
Allen BD Benniston AC Harriman A Llarena I Sams CA 《The journal of physical chemistry. A》2007,111(14):2641-2649
A small series of p-quaterphenyl derivatives has been prepared in which the dihedral angle (phi) for the two central rings is constrained by dialkoxy spacers of varying length. The photophysical properties of these compounds remain comparable, but there is a clear correlation between the rate constants for nonradiative decay of both singlet and triplet excited states and phi in fluid solution. The rates tend toward a minimum as phi approaches 90 degrees . These effects are attributed to the general phenomenon of extended delocalization and can be traced to a combination of changes in the Huang-Rhys factor and the electron-vibrational coupling matrix element, both relating to displacement of the relevant potential energy surfaces and to the medium-frequency vibronic mode coupled to decay. The latter effect arises because of different levels of conjugation in the ground-state molecule. Such findings might have important implications for the design of improved light-emitting diodes. A similar angle dependence is noted for the yield of the pi-radical cation formed on photoionization in a polar solvent, but here, the effect is due to variations in the respective energy gaps between the relevant excited states. 相似文献
90.
低温等离子体转化NO/O2/N2气氛中NO的实验研究 总被引:1,自引:0,他引:1
通过建立低温等离子体实验系统, 研究了介质阻挡放电型低温等离子体反应器作用于NO/O2/N2混合气体系时, NO, O2初始浓度对NO的转化效率的影响以及NOx, O3浓度随能量密度的变化关系. 低温等离子体作用于NO/O2/N2混合气体系时, NO同时发生氧化还原反应, 氧化反应占主导地位, 大部分NO转化为NO2; NO转化率随O2, NO初始浓度增大而降低, 能量密度在450~600 J/L时转化率较高; 产生的O3浓度随能量密度的增大呈先增后减的趋势. 相似文献